Many attempts have been conventionally proposed to manufacture a superconductive conductor by depositing a superconducting layer on a base material.
Energization characteristics of a high-temperature superconductive conductor are known to significantly depend on crystallographic orientation of the superconductor, particular biaxial orientation, particularly on biaxial orientation thereof. In order to obtain a superconducting layer having high biaxial orientation, crystallinity of an intermediate layer as an underlying substance is desired to be improved.
For example, Japanese Patent Application Laid-Open (JP-A) No. 2008-303082 discloses an oriented substrate for forming an epitaxial film, in which an intermediate layer which is provided between the oriented substrate and an epitaxial film formed on at least one surface of the oriented substrate has a multilayer structure of two layers or more, a layer which contacts the substrate is made of indium tin oxide, and, on the indium tin oxide layer, a layer made of nickel, nickel oxide, zirconium oxide, a rare earth oxide, magnesium oxide, strontium titanate, strontium-barium titanate, titanium nitride, silver, palladium, gold, iridium, ruthenium, rhodium, or platinum is used in parallel.
Further, U.S. Pat. No. 6,921,741 discloses a base material for a superconductor which has an MgO layer, which is an intermediate layer formed over a substrate by an IBAD (Ion Beam Assisted Deposition) method (hereinafter, referred to as IBAD-MgO layer), and a material such as CeO2, YSZ, SrTiO3, SrRuO3, LaMnO3, Y2O3, Eu2CuO4, Nd2CuO4, Y2CuO4, or RE2CuO4 are used in parallel on an epitaxially-grown MgO layer formed on the IBAD-MgO layer.